Buddy 150 International Horn Troubleshooting

[az_slynch]

Hey all!

The horn on my '09 St. Tropez 150 quit working recently. I took it apart to troubleshoot the issue and was pleasantly surprised to find that a), the horn is a Stebel Nautilus and b), the supporting wiring is integrated into the wiring harness rather than being an afterthought. For some reason, I'd thought the horn on the Internationals was a slightly quieter Wolo "Bad Boy" and not the Stebel (120dB versus 139dB).

At any rate, the relay turned out to be the culprit. I checked and cleaned the horn button on the handlebar, pulled the relay and tested the wiring sans relay. Horn beeped when the relay socket was bridged and when I measured voltage across the horn button circuit, I had a solid 12.8V when the button was pressed.

Why all the detail, you ask? Well, I wanted to share a subtle issue I found with the relay and replacement part options. If you bridged the horn button pins on the relay with a 9V battery, it would spazz for a second and click closed. It wouldn't do anything with the 12V feed in the scoot. When I measured resistance across the relay coil, I read back 68 ohms. I couldn't find any process for validating the coil value, but I did find a spec for a Wolo 30A horn relay (Model 400-R) that listed a resistance value of ~90.3 ohms on the specifications tab. This relay is electrically identical to the factory relay, so I suspect you could use that resistance value to determine if your old relay has tapped out.

The Wolo relay works perfectly in the Buddy, so it's a good option for replacment and it looks to be readily available at most auto parts stores. The other option I've found is the Vixen VXA7449, which is identical and can be found even more affordably on Amazon.

Hope this bit of info helps the next Buddy International owner with an inoperative horn.

Final note: While under the front cowl, I subbed out the 12V socket for a USB-A / USB-C fast charger that doubles as an LCD voltage display. I can't recommend these enough, as it's nice to be able to get battery status at a touch or check that your stator is providing charging voltage. This is the second one I've installed and the first one is still working fine after two years.